Update timeline "refresh" to reset the timeline, after prompting for confirmation.

lib/controls/timeline/timeline_panel.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:logging/logging.dart';
 import 'package:provider/provider.dart';
+import 'package:relatica/globals.dart';
 import 'package:scrollable_positioned_list/scrollable_positioned_list.dart';
 
 import '../../models/TimelineIdentifiers.dart';
@@ -15,16 +16,15 @@ class TimelinePanel extends StatelessWidget {
 
   TimelinePanel({super.key, required this.timeline});
 
-  Future<void> update(TimelineManager manager) async {
-    await manager.updateTimeline(
-      timeline,
-      TimelineRefreshType.refresh,
-    );
-
-    await manager.updateTimeline(
-      timeline,
-      TimelineRefreshType.loadNewer,
-    );
+  Future<void> update(BuildContext context, TimelineManager manager) async {
+    final confirm =
+        await showYesNoDialog(context, 'Reload timeline from scratch?');
+    if (confirm == true) {
+      await manager.updateTimeline(
+        timeline,
+        TimelineRefreshType.refresh,
+      );
+    }
   }
 
   void scrollToTop() {
@@ -41,7 +41,7 @@ class TimelinePanel extends StatelessWidget {
     final items = manager.getTimeline(timeline);
     return RefreshIndicator(
       onRefresh: () async {
-        update(manager);
+        update(context, manager);
         return;
       },
       child: items.isEmpty

lib/models/timeline.dart

@@ -1,12 +1,15 @@
 import 'TimelineIdentifiers.dart';
 import 'entry_tree_item.dart';
 
+const defaultLowestId = 9223372036854775807;
+const defaultHighestId = 0;
+
 class Timeline {
   final TimelineIdentifiers id;
   final List<EntryTreeItem> _posts = [];
   final Map<String, EntryTreeItem> _postsById = {};
-  int _lowestStatusId = 9223372036854775807;
-  int _highestStatusId = 0;
+  int _lowestStatusId = defaultLowestId;
+  int _highestStatusId = defaultHighestId;
 
   int get highestStatusId => _highestStatusId;
 
@@ -72,8 +75,8 @@ class Timeline {
   void clear() {
     _posts.clear();
     _postsById.clear();
-    _lowestStatusId = 0;
-    _highestStatusId = 0;
+    _lowestStatusId = defaultLowestId;
+    _highestStatusId = defaultHighestId;
   }
 
   @override

lib/services/timeline_manager.dart

@@ -192,9 +192,8 @@ class TimelineManager extends ChangeNotifier {
     late final int highestId;
     switch (refreshType) {
       case TimelineRefreshType.refresh:
-        lowestId = timeline.highestStatusId == 0
-            ? timeline.highestStatusId
-            : timeline.highestStatusId + 1;
+        timeline.clear();
+        lowestId = 0;
         highestId = 0;
         break;
       case TimelineRefreshType.loadOlder: